logo
    Robust microhoneycomb-like nanofibrous aerogels derived from cellulose and lignin as highly efficient, low-resistant and anti-clogging air filters
    26
    Citation
    29
    Reference
    10
    Related Paper
    Citation Trend
    Filtration (mathematics)
    Air velocity
    Air filter
    Turnkey
    The research status of air pre-filters for domestic and foreign machinery vehicles was introduced.The principle,structure and characteristics of typical air pre-filters on market were analyzed.The filtration efficiency,advantages and disadvantages of the typical air pre-filter were described.The existing problems and improvement measures of air pre-filters were proposed.The future development trend and research areas on the air pre-filters were discussed.
    Air filtration
    Air filter
    Filtration (mathematics)
    Citations (0)
    The air supply from an airliner ventilation system is a mixture of outside air and recirculated air that passes through a high efficiency particulate air (HEPA) filter. The effectiveness of two commercial-available airliner cabin air filters were investigated in laboratory-based measurements due to the practical restrictions on airliner cabin filter testing during usage. The filtration efficiency and pressure drop were assessed at a particle size range of 20–500 nm under various airflow rates throughout the filter usage period. The Most Penetrating Particle Sizes (MPPS) were observed at ~150 and ~55 nm, where the filtration efficiency was 86% and 99% at the rated airflow rates (1600 m3/h and 1970 m3/h), respectively. The filtration efficiency decreased in response to the increased airflow rate from 1000 m3/h to 2200 m3/h, with the greatest reduction (~10%) occurring at MPPS. An increase of 250 Pa in the pressure drop across the filter was observed as the airflow rate increased from 1000 m3/h to 2200 m3/h. Increased filter usage led to increases in both filtration efficiency and the pressure drop. The actual filter usage was estimated using dust loading in the laboratory. Filtration efficiency increased ~10% and the pressure drop increased ~800% when 220 g/m2 dust was loaded on the filer, corresponding to ~6000 hours filter usage at an in-cabin PM10 concentration of 100 μg/m3. Explicit relationships among filtration efficiency, pressure drop and filter usage under various in-cabin particle concentrations are presented as a reference to facilitate the use of more appropriate airliner cabin air filter exchange periods.
    HEPA
    Filtration (mathematics)
    Air filter
    Air filtration
    Particle (ecology)
    Citations (25)
    Abstract. A model is proposed to predict the resistance of airflow through the interconnected pores between grain kernels. The model is based on the tortuous airflow paths and a collection of a straight and three branching tubes along the airflow paths through grain bulks. The straight and three branching tubes are constructed from the Discrete Element Method (DEM) simulation of the grain bulks. The resistance to flow along a flow path is predicted as the total pressure drop of the straight tube and three branching tubes of each tetrahedron units. The predicted pressure drop is compared with the average pressure drop for airflow through grain beds in ASABE Standard and the pressure drop predicted by Ergun’s equation. The predicted total pressure drop for airflow through the widest airflow path is 17.9 Pa, which is close to the data from the ASABE Standard. It indicates that the pore-scale fluid flow model integrated with the DEM pore structure model is feasible to predict airflow resistance along the flow paths in grain bed.
    Citations (0)
    For pressure drop reduction and collecting efficiency incretion of the air filter,using computational fluid dynamics(CFD) simulation technology and combineing with the way of experimental test,particles trajectories and distribution rate of deposition in air filters were calculated simulatively,the position where the particles reside easily was obtained.According to experimental data of collecting efficiency,multi-relation calculation formula of filtration media collecting efficiency was proposed.By building 2D and 3D model of CFD,flow field distribution and filtration pressure drop of air filters were simulated,the results of computer simulation were in agreement with experimental test results basically.Using simulation model and changing structural parameters of air filters to instead parts of experimental research,variation and formula of relationship between the filtration pressure drop and its significant single-factor impact of air filters were obtained.Based on a large number of simulation data,multi-relation calculation formula of relationship between the pressure drop and its structural parameters of air filters was proposed using regression analysis.
    Air filter
    Filtration (mathematics)
    Citations (1)
    Operating rooms for patients undergoing infection-prone surgery often have unidirectional flow supply air systems. Many systems installed in Europe have low air velocities, i.e. equal and below 0.3 m/s, while other supply air systems have velocities about 0.4 m/s. The velocity, given by the supplier, is mostly the inlet air velocity just below the filter screen of the unidirectional flow system. The purpose of this paper is to describe contamination risks in unidirectional airflow without obstacles at different air velocities. To evaluate contamination risks, the method for limitation of risks, the LR-Method, has been used. The results show that the convection flows and arm movements from a person standing in the unidirectional airflow system have a great impact on the contamination risks at air velocities below 0.4 m/s and that the air velocity should at least be 0.4 m/s to achieve a good protection efficacy.
    Air contamination
    Air filter
    Air velocity
    Citations (0)